Process of separating liquid from solid fatty acids.



' paratus 0 ."watr is held in a sponge.

UNITED STATE-S PATENT OFFICE.

ERNST TWITCHELL, OF WYOMING, OHIO.

mass or samm'rmc mama Fisok' sou FATTY acr'ns.

Specification of Letters Patent.

rammed a mzo, 1909.

Application filed November 11, 1907. Serial No. 401,619,

To all whom it may concern:

. aratin Liquid from Solid Fatt Acids,

of which t e following is a specification.

The object of my invention is to produce an industrial chemical process for separating from a common source the fatty acids which are solid at normal temperature, (of which stearic acid is. an example), from those other fatty acids which are liquid at normal temperature, (of which group oleic' maly be cited as a familiar example.)

How and other solid fats of animal or vegetable origin contain lycerin, which is separated out by the wellmown saponification rocess. The remaining tallow is practical y an intermixture of stearic and oleic fatty acids, the stearic acid being a solid and the liquid oleicacid being physicall' contained within the interstices formed y the crystals of thestearic acid, very much as The most familiar process "-for separating these fatty acids one from the other, is the physical operation of pressing the fatty acid cake within-a cloth. This 0 eration is slow and exensive as .onl sma l cakes of fatty acid can be convenient y handled.

By my 'rocess, large tanks and other'apf a type familiar to the industrial organicchemical arts may be emplo ed, so as to reduce. to a minimum 'the mechanical and manual operations and to handle the products in large quantities on a cheap commercial basis. p

I have: discovered that sulfo-fatty acid is soluble inthe liquid fatty acids and is also acid. Sulfo-fattyacids are soluble in the soluble'in water, so that this process depends upon this mutual solubility, by means of which water may be made to separate out the liquid fatty 'acidfrom the solid fatty lifluid fatty acids, but the member of the s fo-fatty acid group which I refer to employ as the reagent is the su fo-fattyaromatic acid, described in my Patent No. 628,503, elatedJuly 11, 1899, although 1t 1s alsopossible'to use simple sulfo-fatty acid -I or any water soluble combination thereof. The claims therefore are to be read with the upderstanding that these reagents are equiva ents.

The preferred method of practicing the process is to melt the mixed fatty acids in a suitable vessel or tank, introducing and thoroughly intermixing a relatively small percentage (say one er cent.) of a sulfo fatty acid, or better, t e sodium salt of this acid. The sulfo-fatty acid dissolves in the agent dissolved in the li uid oleic acid, and

the solution containedp ysically inthe solidified cake much as in the original cake,

but with the oleic acid now slightly soluble in water by virtue of its having a sulfo-fatty acid in solution. This solidified cake is then preferably comminuted and washed withwater. The water being slightly soluble in the -oleic acid solution, emu sifies this solution and theemulsion is-then washed away with the water. If the original cake is comminuted and washed with water alone the oleic acid doesnot emulsify and the water does not touch the liquid oil or wash it away in any appreciable degree.

lVithout attempting an accurately scientific definition of the emulsifying action, a general mental conception ma be formed of this process; the slightsolubility of the wash water in the oleic and sulfofatty acid solution produces such a slight but suflicient degree of the action of solution as to enable the water, as it were, to mechanically penetrate into the oleic acid and sulfo-fatty acid solution, so that so much of this solution asis not dissolved in the water is physically broken up intd minute globules forming a milky or turbid mixture, which is known as anemulsion, and which emulsion is mechanically carried oif by the washing operation. lVhenthe-wash water is allowed to stand the oil or'oleic acid containing the sulfo-fatty in the water after the decantation is so slight as to be of no material consequence, although it may be "removed if desired, by a subsequent process which I need not here describe.

Anotherway of effecting this process is to first dissolve the sulfo-fatty acid, or its sodium salt, in the water and then to wash the cake, or a comminuted mass thereof, with the water charged'with the reagent. Here again the oleic acid is slightly soluble .in the water solution of the sulfo-fatty acid and the emul I sifyingand Washing process are the saine'as fatty acid, say with one per cent. of sulfuric' acid, or with common salt,- which does not affect its solubility inoleic acid, butv renders chic and sul it less soluble in Water, Without in any Wise 5 effecting the emulsifying and washing process dependin upon the slight solubility of fo-fatty acid in water. It does not matter very materially Whether the sulfo fatty acid is first dissolved in the liquid fatty acid 'or. in the Water.

This process is very simple and complete, and can be economically carried on in connection with the various chemical industrial arts engaged in handling this class of products. I v K The present mechanical separation is an intermittent operation carried on through tlieagency ofsmall presses. My new. method may not only be continuous, but may be practiced on a large industrial-scale with superior results in both prodnets and process.

Having described my invention, I claim ,1. The herein described process of separating intermixed solid and liquid fatty acids from one another, which consists in dissolving in the liquid fatty acid a relatively. small per cent. of a sulfo-fatty acid, Washing out With Water the liquid fatty acid from the solid and decanting the liquid. oil from the Wash Water, substantially as described;

. 2. The herein described process of separating the liquid from the solid fatty acids, which consists in emulsifying and 'Washing the liquid fatty acids from a mixture thereof the liquid fatty acids from the mixed comminuted source, substantially as described.

4. The herein described process of separating the liquid from the solid fatty acids,

which consists in subjecting them to the joint action of watenand sulfo-fatty acid,. sub- .st'antially as described.

In testimony whereof, I have hereunto set my hand.

ERNST TWITCHELL.

Witnesses OLIVER B. Kaiser, LE0 ODONNELL. 

